HIV Viral Load
Reviewed
Also called: nucleic acid testing, NAT, nucleic acid amplification test, NAAT, HIV PCR, RNA Test
An HIV viral load test measures the amount of HIV in a sample of your blood.
Specimen: Blood sample from a vein
Urgent safety information
If you think you were exposed to HIV, talk with your provider right away about getting tested. You may also be able to have emergency treatment to prevent HIV infection within the first 3 days after a possible exposure.
Why this test may be ordered
- To guide decisions about HIV treatment after diagnosis
- To check how well HIV medicines are working
- To monitor changes in your HIV infection (getting worse, stable, or better)
- To diagnose HIV in newborns born to a person with HIV
- In certain cases, to diagnose HIV after a high-risk exposure or when early symptoms are present
Preparation and collection
You don't need any special preparations for an HIV viral load test. But if you are getting this test to find out if you are infected with HIV, you should talk with a counselor before or after your test so you can better understand the results and your treatment options.
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
Understanding results
Your provider needs to compare your test results over time to see if your viral load is going up or down, and different tests from different labs can be difficult to compare.
- Undetectable (monitoring): A negative or undetectable viral load means that you have so little HIV in your blood that the test can't find it. This means that your HIV medicines are working well to protect your immune system, and you are unlikely to spread HIV through sex. Limitation: It does not mean you're cured. Next step: You must continue to take your medicines as prescribed to keep your HIV in control.
- Low viral load (monitoring): A low viral load means your medicine is stopping the virus from growing and your infection is unlikely to get worse. Limitation: Your provider needs to compare your test results over time to see if your viral load is going up or down, and different tests from different labs can be difficult to compare. Next step: You must continue to take your medicines as prescribed to keep your HIV in control.
- High viral load (monitoring): A high viral load means the virus is growing and your treatment is not working well. The higher the viral load, the more risk you have for infections and diseases related to a weak immune system. Limitation: It may also mean you have a higher risk for developing AIDS. Next step: If your results show a high viral load, your provider will probably change your medicines.
- Negative (diagnosis): A normal or negative result means that no HIV was found in your blood, and you are probably not infected with HIV. Limitation: But if you are getting this test to find out if you are infected with HIV, you should talk with a counselor before or after your test so you can better understand the results and your treatment options. Next step: If you have questions about your results, talk with your provider.
- Any virus detected (diagnosis): A result that shows any amount of virus in your blood means you have an HIV infection. Limitation: ART can't get rid of HIV completely, so you'll need to take medicines for the rest of your life. Next step: Your provider will likely order other tests, including a CD4 count, to see how much HIV has damaged your immune system.
- An undetectable viral load does not mean you are cured; you must continue taking your medicines as prescribed.
- A negative diagnostic result means you are probably not infected with HIV, but follow-up testing may be needed after a high-risk exposure.
- HIV viral load tests are expensive and are typically used after a positive screening test, unless you have a very high risk of infection.
- For diagnostic testing, counseling before and after the test is recommended to help you understand the results and your treatment options.
What to do next
If you are living with HIV, you will have regular viral load tests to monitor your infection and treatment. It's best to have the same type of test done at the same lab if possible.
- What does my viral load result mean for my treatment plan?
- How often should I have this test?
- Can my viral load become undetectable even if I have HIV?
- What should I do if my viral load is high?
- Do I need any other tests to monitor my HIV infection?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.